Why the Metric System Might Be Screwed

International Bureau of Weights and Measures
International Bureau of Weights and Measures

The world’s most perfect weight isn’t so perfect anymore. And that has scientists scared.

Hidden in a vault outside Paris, vacuum-sealed under three bell jars, sits a palm-sized metal cylinder known as the International Prototype Kilogram, or “Le Grand K.” Forged in 1879 from an alloy of platinum and iridium, it was hailed as the “perfect” kilogram—the gold standard by which other kilograms would be judged.

Although it’s arguably the world’s most famous weight, Le Grand K doesn’t get out much. Since hydrocarbons on fingertips or moisture in the air could contaminate its pristine surface, it goes untouched for decades, under triple lock and key at the International Bureau of Weights and Measures. Every 40 years, however, it makes an appearance. The weight is ushered from its chamber, washed with alcohol, polished, and weighed against 80 official replicas hand-delivered from laboratories around the world. Today, whenever scientists need to verify something is precisely one kilogram, they turn to one of these replicas, over which Le Grand K reigns supreme.

This system sounds absurd, but not too long ago, lots of units relied on similar methods. The kilogram was just one of seven standards of measurement established by the French Academy of Sciences in 1791, all based on physical prototypes. These benchmarks caught on worldwide because standardization was sorely needed. At the time, some 250,000 different units of weights and measures existed in France alone, which meant that the only constant was complete chaos.

Weight Problem

While basing measurements on tangible benchmarks was an improvement, using physical standards wasn’t without its flaws. For one, they have a nasty habit of changing. In Le Grand K’s case, it’s been losing weight. At its most recent weigh-in in 1988, it was found to be 0.05 milligrams—about the weight of a grain of sand—lighter than its underling replicas. Experts aren’t sure where this weight went, but some theorize that the replicas have been handled more often, which could subtly add weight. Others postulate Le Grand K’s alloy is “outgassing,” which means air is gradually escaping the metal.

Whatever the reason for Le Grand K’s gradual wasting away, it’s got scientists scrambling for a more reliable standard. Some argue that this is long overdue, since all other units of measurement are already defined by fundamental constants of nature that can be reproduced anywhere anytime (provided you’ve got some sophisticated lab equipment). The meter, for example, used to be defined by a metal rod stored alongside Le Grand K. But in 1983, it was redefined as the distance light travels in a vacuum during 1/299,792,458 of a second.

Standardizing the kilogram has been trickier, though. Australian scientists are polishing a one-kilogram sphere of silicon, hoping that they’ll be able to count the number of atoms it contains to create a more accurate standard. American physicists at the National Institute of Standards and Technology (NIST) are attempting to redefine a kilogram in terms of the amount of voltage required to levitate a weight. But so far, neither approach can match Le Grand K’s accuracy.

Why should we care whether a kilogram in a vault is “perfect” or not? Because it’s bad news when your standard is no longer standardized. While no one’s worried whether a single kilogram of apples is a hair lighter or heavier at the produce stand, a small discrepancy can become a gargantuan one if you’re dealing with, say, a whole tanker of wheat. The kilogram is also used as a building block in other measurements. The joule, for instance, is the amount of energy required to move a one-kilogram weight one meter. The candela, a measure of the brightness of light, is measured in joules per second.

These links mean that if the kilogram is flawed, so are the joule and candela, which could eventually cause problems in an array of industries, particularly in technology. As microchips process more information at higher speeds, even tiny deviations will lead to catastrophes. Le Grand K’s unreliability “will start to be noticeable in the next decade or two in the electronics industry,” warns NIST physicist Richard Steiner. If your next smartphone is buggy, you’ll know which hunk of metal to blame.

So scientists continue to chase the perfect kilogram. “Maybe we have all been looking for too high-tech an answer,” says Stuart Davidson of England’s National Physical Laboratory. “There could be something really obvious out there we’ve missed.” The NPL’s website encourages others to give it a shot: Any better ideas on a postcard please. Until then, Le Grand K will remain king—short of true perfection, but as perfect as it gets.

How to Relieve a Tension Headache in 10 Seconds, According to a Physical Therapist


The source of a pounding headache isn't always straightforward. Sometimes over-the-counter painkillers have no effect, and in other cases all you need is a glass of water to ease the pain. When it comes to a specific type of a headache, Prevention recommends a treatment that takes about 10 seconds—no fancy medications or equipment required.

If you're experiencing pain throughout your head and neck, you may have a tension headache. This type of headache can happen when you tense the muscles in your jaw—something many people do when stressed. This tightening triggers a chain reaction where the surrounding muscles in the head and neck become tense, which results in a painful, stiff feeling.

Fortunately, there's a way to treat tension headaches that's even easier than popping an Advil. David Reavy, a physical therapist known for his work with NFL and NBA athletes, recently suggested a solution to Prevention writer Christine Mattheis called the masseter release. To practice it yourself, look for the masseter muscle—the thick tissue that connects your jawbone to your cheekbone on either side of your face—with your fingers. Once you've found them, press the spots gently, open your mouth as wide as you can, close it, and repeat until you feel the muscle relax. Doing this a few times a day helps combat whatever tension is caused by clenching your jaw.

If that doesn't work, it's possible that the masseter muscle isn't the source of your headache after all. In that case, read up on the differences among popular pain killers to determine which one is the best match for your pain.

[h/t Prevention]

Why Do Hangovers Get Worse As You Get Older?


“I just can’t drink like I used to” is a common refrain among people pushing 30 and beyond. This is roughly the age when it starts getting harder to bounce back from a night of partying, and unfortunately, it keeps getting harder from there on out.

Even if you were the keg flip king or queen in college, consuming the same amount of beer at 29 that you consumed at 21 will likely have you guzzling Gatorade in bed the next day. It’s true that hangovers tend to worsen with age, and it’s not just because you have a lower alcohol tolerance from going out less. Age affects your body in various ways, and the way you process alcohol is one of them.

Because your body interprets alcohol as poison, your liver steps in to convert it into different chemicals that are easier to break down and eliminate from your body. As you get older, though, your liver produces less of the enzymes and antioxidants that help metabolize alcohol, according to a study from South Korea. One of these enzymes—called alcohol dehydrogenase (ADH)— has been called the “primary defense” against alcohol. It kicks off the multi-step process of alcohol metabolization by turning the beer or booze—or whatever you imbibed—into a chemical compound called acetaldehyde. Ironically, this substance is even more toxic than your tipple of choice, and a build-up of acetaldehyde can cause nausea, palpitations, and face flushing. It usually isn’t left in this state for long, though.

Another enzyme called aldehyde dehydrogenase (ALDH) helps convert the bad toxin into a new substance called acetate, which is a little like vinegar. Lastly, it’s converted into carbon dioxide or water and expelled from your body. You’ve probably heard the one-drink-per-hour recommendation, which is roughly how long it takes for your liver to complete this whole process.

So what does this mean for occasional drinkers whose mid-20s have come and gone? To summarize: As your liver enzymes diminish with age, your body becomes less efficient at metabolizing alcohol. The alcohol lingers longer in your body, leading to prolonged hangover symptoms like headaches and nausea.

This phenomenon can also partly be explained by the fact that our bodies tend to lose muscle and water over time. People with more body fat don’t break down alcohol as well, and less water in your body means that the booze stays concentrated in your system longer, The Cut reports. This is one of the reasons why women, who tend to have a higher body fat percentage than men, often suffer worse hangovers than their male counterparts. (Additionally, women have fewer ADH enzymes.)

More depressingly, as you get older, your immune system deteriorates through a process called immunosenescence. This means that recovering from anything—hangovers included—is more challenging with age. "When we get older, our whole recovery process for everything we do is harder, longer, and slower," gastroenterologist Mark Welton told Men’s Health.

This may seem like a buzzkill, but we're not telling you to put down the pint. However, if you're going to drink, just be aware of your body’s limitations. Shots of cotton candy-flavored vodka were a bad idea in college, and they’re an especially bad idea now. Trust us.

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